This invention relates to a method for continuously dyeing textile fabrics containing blends of synthetic fibers and cellulosic fibers.
Fabrics formed of blends of synthetic and cellulosic fibers, such as 50/50 blends of polyester and cotton, 50/50 blends of cotton and acrylic, and 75/25 blends of cotton and nylon for example, pose many problems in dyeing since the different fibers in the blend each have their own dyeing requirements and special peculiarities. In the case of a fabric formed entirely of polyester fibers, a method of dyeing with disperse dye commonly known as the thermosol process may be employed for continuously dyeing the fabric. However, most apparel fabrics are blends of polyester with a cellulosic fiber, as noted above, and these blends cannot be continuously dyed by the thermosol process.
Moreover, different classes of dyestuffs are needed for the different fibers, and the dyeing is usually accomplished in a two-step process. The cellulosic portion of the blend is dyed by a batch method using reactive dyes or direct dyes which require large volumes of water that must be heated to boiling for many hours, and with large amounts of auxiliary chemicals being used. After the cellulosic fibers have been dyed to the correct shade, the polyester or other synthetic portion of the blend is then dyed with disperse dyes with a similar energy/time/chemical requirement.
The disadvantages of the aforementioned multistep dyeing process have been recognized, and attempts have been made to provide a process which overcomes these disadvantages. For example, the publication entitled "A Cost Effective Approach to Dyeing Cotton Tubular Knits", Textile Chemist and Colorist, Volume 13, No. 4, pages 37-39 (April 1981) describes a pad/batch dyeing process promoted by Cotton Inc. of Raleigh, North Carolina, which is a hybrid of pad dyeing and batch dyeing. However, this pad/batch process still suffers a number of disadvantages and limitations and has not been widely adopted commercially.
It is an object of the present invention to overcome the aforementioned disadvantages and limitations of the prior processes available for dyeing blends of synthetic fibers and cellulosic fibers.
More particularly, it is an object of the present invention to provide a process in which textile fabrics containing blends of synthetic fibers and cellulosic fibers may be continuously dyed quickly and in a cost effective manner.